Toward Understanding Stability of RF MIS-HEMTs under ON/SEMI-ON/OFF-State Pulses with Scaling in-situ SiN Thicknesses

This study examines the stability of RF MIS-HEMTs under ON, SEMI-ON, and OFF-state pulses with in-situ SiN thicknesses scaled from 10nm to 1nm, compared to RF Schottky HEMTs. While stability is maintained under ON-state pulses, significant degradation is observed under SEMI-ON and OFFstate pulses, particularly in devices with a 1 nm in-situ SiN layer (M1). The high interface trap density (Nit) and inadequate passivation of the M1 sample contribute to the observed current degradation. EDX analysis suggests a rough interface in M1, likely due to non-uniform SiN growth or SiN/Al2O3 intermixing.